Gas-operated firearm



(No Model.) 4 Sheets-Sheet 1.

G. JOHNSON. r

' GAS OPERATED FIREARM.

No. 532,380; P tented Jan. 8, 1895.

(No Model.) 48heets-Sheet 2.

v G. JOHNSON.

GAS OPERATED FIREARM.

No. 532,380. Patented Jan. 8, 1895.

wi liheoow m/ K "K E Q Q J 4 Sheets-Sheet 3. c. JOHNSON. I

G'AS OPERATED FIREARM.

Em Patented Jan. 8, 1895.

(No Model.)

4 Sheets Sheet 4. .0. JOHNSON.

GAS-OPERATED FIREARM. N0. 532,380. I Patented Jan. 8, 1895.

NITED STATES PATENT OFFICE.

TO OLE HA SEN, or

CHOATE, MIoHIeAtt.

GAS-OPERA'IZED FIREARM.

SPECIFICATION forming part of Letters Patent No. 532,380, dated January 8. 1 895.

Application and March 1,1894.

To all whom it may concern.-

Be it known that I, CHRIST JOHNSON, a citizen of the United States of America, residing at Wausau, in the county'of Marathon and State of Wisconsin, have-invented'certaiu new and useful Improvements inMagazine- Guns, of which the followingis aspecification, reference being had 'to the accompanying drawings.

This invention relates to certain. new and useful improvementsfn fire arms and particularly to that class known as magazine guns.

The primary object is to provide-an ex tremely simple and inexpensive combination of parts, together with means for automatically operating the same, whereby all manual manipulation required with arms in use at thehpresent day, shall be entirely dispensed wit Furthermore, the invention contemplates the employment of a novel and peculiar construction of parts, whereby the expansive force of the gas generated by the explosion of a cartridge may be utilized and properly directed to actuate certain power transmitting mechanism and effect the withdrawal or extraction of the exploded cartridge, and the final ejection of the same, also the elevation and placingof a loaded cartridge in firing? position and the readjustment of the breech bolt.

With these and other objects in view various combinations and arrangements of parts are employed, which will be hereinafter more 5 fully set forth, and specifically pointed out in the claims.

In describing the invention in detail, referonce is had to the accompanying drawings, forming part of this specification,an d wherein like letters indicate corresponding parts in the several views, in which- Figure 1 isa view in side elevation of a magazine gun, showing a preferred construction arranged to embodymy improvements. Fig. 2 is a vertical longitudinal section of the same, showing the mechanism in firing position. Fig.6 is a similar view showing the mechanism in action. Fig. 4 is a view in cross section, taken about line as, w, of Fig. 2. 5o F1gs.5 and 6 are detail views in elevation and perspective of the breech-bolt locking device.

shin No. 501;936. (Remodel-l Fig. 7 is a view in cross section taken on the line -yy-of Fig. 2. Figs. 8 and 9 aredetail sectional views of the breech-bolt actuating gearing. Figs. 10 and llare detail views in elevation of the cartridge carrier. Fig. 12 is a sectional view taken on the line a, m, of Fig. 1. r

In the drawings:-A. denotes the receiver of the gun proper; B, the stock; 0, the breech 6 mechanism; D, the barrel, and E the magazine formed in the tip stock 6 and provided with the well-known form of spring pressed follower for feeding the cartridges on to the carrier F. I

Suitably secured to'the exterior at one side of the receiving well --bis an upwardly in clined cylinder g which is headed and provided with a piston g fitting air-tight, and a rod.-'g and communicates with the barrel through the wall of the barrel and terminates'adjacent the inner end of the shell of the cartridge, for a purpose to be hereinafter explained.

The 'piston-rod g*--- is encircled by a retractile spring g which is inclosed within the cylinder and serves to normally retain the piston at the upper end of the cylinder, as is indicated by dotted line in Fig. 1. Forming r a continuation of this piston-rod is a toothed 3 rack bar -g which. is adapted to periodically engage a pinion g"- mounted on a transversely journaled shaft -'K-. At the outer end and from opposite sides of this rack, two studs g project in opposite directions and enter interior guides -g of a short cylindrical casing -'-gwhich latter is suitablyfattach'ed to the stock. These guides are curved at the ends so as to cause the toothed bar or rod to partially rotate on each stroke thereof, thatis to say, on the-out stroke of the red, the toothed surfacethereof will face outward, so as to move by the pinion without engagingthe same and owing to the 'terminal curvature of the guides, the rod'at the end of its travel will be partially rotated, thus bringing the toothed face into mesh with the pinion. The teeth of the rod preferably correspond in number, with those of the pinion or are otherwise suitably arranged 50 that the latter will make a complete revolution during the back-stroke, which results in ef- Fig. 2.)

. block -I which latter is slidingiy mounted in position and consists of a bar -'iprovided at one end with a firing pin ---i and at the other end wi ih a suitable projection or seat-i"'- to receive the i mpact of the hammer -J-- said breech block also having the un dcr side thereof adjacent said projectiomcu t away to'form a notch -2I" for the receptio n of a spring actuated lock-bolt h--. This bolt has a liinited vcrtical movgment in suit-- able guides -7z and is normally held engaging the notch of the breech-block by an upwardly acting spring 7r mounted in a recess of this bolt -7i and at right angles to the length of the same, is a latch -h one arm of which projects through an opening in the sidewall of the receiving well and is adapted to he engaged by the radial projection of the pinion aforesaid. The arm is also providedwith a stud h which onters an inclined guideslot h formed in the face of one of the boltguides h (See Thus as the arm is depressed by the rotary movement of the radial projection -g'- the inclination of the slot --h will tend to draw said arm inwardly until it finally becomes disengaged from said projection, thereby allowing the pinion to continue its rotation.

As the latch is partially depressed, it overcomes the resistance of thespring h and carries downwardly the lock-bolt -hthereby rclcasin g the breech-bolt -I which latter is immediately moved outwardly against the action of its spring --r"- by the rcvolvi ng pin-.

ion 7r engaging the rack ,or toothed surface-'i" thereof. These snccessivestepslast described, are made to follow closely one after the other, by the following arrangement of parts: Slidingly mounted on a square portion of the shaft -7; which carries the fixed pinion -.-y and the loosely mounted pinion -7v"- is a disk -7:?- from which two lugs or studs 7; 7t"-- project respectively, radially and axially. The former, located on the periphery, enters a cam guide-slot k (see Fig. 7) which causes the disk when rotated to move to and from the pinion -k'-E This slid- I ing movement is utilized to effect alockin g ongagement between the lug 7r, above described-and a similar lu-7c ro ecting in moved along the shaft suflicicntly the opposite direction from the pinion -k'. Thus assuming the several members to be in their normal position, as shown in Figs. 2 and 7, that is, with the radiallng resting centrally of a deprcssion 7.-F- in the cam guide-slot, from which it follows, that the wheels would be separated, the lug -it-"'- slightly in advance of the lug ]r and the parts -h"' engaging. As the pinion -g is 1'0- tated motion will be imparted directly to the disk 7r?- "ausingthc lug 7;-- o ride out of the depression, l lllt before the disk has been to effect an Slidingly l interlocking of the lugs -7a7t the bolt -7rwill be actuated as before stated, and immediately following this step the lugs are brought into engagement, and the pinion thereby rotated sufficiently to move the breech-bolt outwardly until properly checked. During the outward travel of this bolt, its spring is compressed and as the lugof the disk again enters the depression and becomes disengaged from pinion -kthe spring acts, forcing the breech-bolt home and reversing the rotation of the pinion k' which latter assumes it normal position, with its lug slightly in advance of the lug k at the same ti me, the locking-bolt --h-- actuated by its spring, is forced into the notch -iand thereby secures the breech-bolt rigidly in position.

The carrier -'--F comprises a pivoted earriage -fprovided with a cartridge receiving seat f 1 and is slotted as at -f Into this slot a'pin -f -.of a slide f proj ects. The slide runs in suitable ways f*-' with a projection thereof entering a slot or recess -F of the breech-bolt, the end walls of which form shoulders 1J adapted to abut against the projection and force the slide back and forth. This-motion serves to ole vate and depress the carriage by reason of the pin and slot connection.

The operation is as follows: With the parts in position as illustrated by Fig. 2; as the cartridge is exploded a portion of the gas finds escape through the port -gand owing to its expansive force the piston -g is driven downwardly ing the spring -*g and the toothed rod moved rearwardly but not engaging the pinion. At the limit automatically shifted and the reaction of the spring retracts the piston. It is this movement that is u mechanism and is first imparte ion by the rack. As thepinion is rotated through one-twelfth to one-tenth of a revolution its radial projection first depresses the lock-bolt h.- to release the breech-bolt and the remaining portion of the rotary movement is transmitted to the pinion -.-kas above set forth, to force said breech-boll: outwardly and compress its spring. This cutward movement of the boltwithdraws the exploded shell in the'usual manner by means of the spring-clamp jaws z'- and ejects it in a manner-and by any means well known in the art. At the same time the shoulder-i bringing up against the projection of the slide, forces it outwardly and thereby elevates the carriage and places the cartridge in proper position to be engaged and forced into the breech by the breech-block.

It will be noted that when the carriage is elevated, a portion of the forward end partially covers the entrance to the magazine thus effectually preventing the escape of the cartridges therefrom. The breech-bolt is retained in the outward position until the pinto the pinin the cylinder, compress of the stroke, the rod is tilized to'actuate the breech into the breech and secured by.the self-acting lock-bolt -Z forcing up into the notch of the breech-bolt.

- It will be observed that the carrier is not depressednntil after the shell has been forced home, since the shoulder of the bolt I- is so relatively arranged thatit does not engage the slide until after this step in the operation has been performed. Furthermore,it will be apparent that everypart automatically as sumes its normal position and particularly the disl; and pinion "7t'*'7c and their en.- gaging ln gs, preparatory to thenext discharge of-the arm;

'I do not wish to be understood as limiting myself to the exact construction herein illustrat-edand described, as various changes may be made in the same without materially departing from the present invention.

Having fully described my invention, what 1. Ina fire arm, the combination of a barrel adapted for the reception of a'cartridge, of a vent adjacent the breech, a cylinder communicating with the vent, a piston rod and toothed rack bar integral therewith, working in the cylinder and suitable connections between the toothed rack bar 'and the breech bolt, whereby the breech'mechanism is operated, for the purpose described. 7 2. In a fire arm, the combination with the barrel suitably stocked,of a ventleadin g from the breech,-a cylinder communicating with the vent, a piston rod and integral toothed rack bar working in the cylinder, and means for throwing the rack bar into engagement with'a pinion and suitable connections between the pinions and the breech bolt, where-,

by the breech mechanism is operated for the purpose described.

3. In a fire arm, the combination of a barrel having a vent, a cylinder communicating with the vent, a piston rod working in the cylinder having an integral rack bar the end thereofoperated in a guide by which the rackbar-is periodically rotated, a pinion engaged by the rack bar, a spring held breech bolt, a device for looking said bolt tnd means for operating the bolt locking mechanism,'through the rack bar and pinion for the purposedescribed.

'4. In a fire arm, the combination with a bar rel having a vent, of a cylinder communicating with the vent, a piston operating the pis- ,ton rod, and integral rack bar, a breech belt,

a device for locking the bolt, a cartridge carrier operatively connected to the bolt and receiving motion therefrom and means for operating the breech mechanism bythe connection between the rack bar and breech bolt, substantially as described by a portion of the en: orgy in the gascaused by the explosion of the cartridge, through the connection between the cylinder, rack bar and breech mechanism for the purpose described.

. 5. In a fire arm, the combination with the barrel having a vent, an exterior cylinder communicating with said vent, a piston rod having an integral rack bar working in the cylinder, a spring held breech bolt and a device for locking said bolt, and means between the breech bolt and the rack bar for unlocking said bolt and'for actuating the breech mechanism by the rack bar for the .purpose described.

In testimony whereof I affix my signature inpresence of two witnesses.

, CHRIST JOHNSON.

Witnesses:

FRED. GENRICH, JOHN J OHNSON. 

